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' T. MELLOR. BLACKBOARD. APPLICATION H LED NOV. 5. 1918.

1,318,681. Patented Oct. 14,1919.

M a g m1 0:: ,r --P 4 THE COLUMBIA PLANOOR APH c0.. WASHINGTON, D. c.

myinventionp p a V Fig. 2 represents an enlarged detailed UNITED s'rn'wmvr orFIoE.

TOM MELLOR, or BRANDON, MANITOBA, chasm.

' rLAcKBoAaD.

T 0 all whom it may concern: v

Be it known that I, TOM MELLOR, of the city. of Brandon, in the Province of Manitoba, Canada, have invented certain new and useful Improvements in Blackboards, of which the following is the specificationf The invention relates to improvements in blackboards, particularly as used in schools and other public places, and the object of th invention is to provide a blackboard arranged and constructed so that it will not reflect light directly" into the eyes of the pu pilsor observer's, thereby allowing any material on the blackboard'to be plainlyvisibleto all observers. .'A further object ofltheyinventionr is to provide a blackboard which can be readily adjusted by the manipulation of a hand wheel and which is arranged so that it will remain set in the adjusted position. 'A' still further object of the invention is to provide an adjustable means for setting the blackboard at a desired inclinatiom suoh means being aisoarmnged softhat the blackboardban-b'e locked againsttampering in the upright position.

- A' un further object isle arrange as parts so that they can be readily installed on awall; and operated;

1 'VVith the abOVeobJeCt-s in view theci'nvention consists essentially in a blackboard pivoted at the loweredge, 'a windingshaft,

a worm wheel on ,theshaft, a wornrengaging the worm wheel, a hand wheel'jfor inanipulat i ng the worm, flexible wlndi'ngconnections between the winding shaft, and the free edgeof the blackboard guides for the flexible winding connections and springs interposedb'etween the free edge ofth'e blackboard'and the supporting wall, the parts being arranged and constructed as hereinafter more particularly described andlater pointed'out inthe appended claims," reference being had to the-accompanying drawing in which:--

Figure 1" represents a front view of-a blackboard 1 constructed in accordance with vertical sectional- View through the blackboard and operating parts; I

1 Fig. 3 represents a side view of one of the brackets,

Fig. 41 represents afrontview of one of the brackets.

centered rectangular frame 3! comprising with the usual Specification of Letters Patent. Pate td Oct, 14;, 1919. Application filed. November 5, 1918. Serial No 261,276.

on the size oftheroom and the requirements and'that itcan be attached to the wall of the room orto' any other solid support.

-11 represents the wall of a room and 2the blackboard which is adjustably suspended 'frointhe wallin a inannershortly' described, being elevated severaffeet from 'the floor as is customary 1118011001 rooms and other such public places where blackboards are used. V

The bl-ackboard'is formed from an open top' and bottonistrips L and 5 connected by end strips 6 and 7, the open center of the fr me being closed by-backing boards'f8 passing between the top and bottom menibers l and "5 of the frame.

AS willbebbserved these backing boards are set into the frame by suitably grooving the top and bottom members and. the material forming the writing surface, such as slate 9, is placed in. thefrarne'against the backing boards and 'is held at the .top and ends by molding strips 10 and at the bottonr'bya chalk rail 11; the

inolding'strips and chalk rail being'permanently secured such as'by nailing or screwing to the frame. The chalkrail is supplied lengthwise extending chalk groove 12. .7

The strip ,5fis provided on the underside with a lengthwise extending tongue 13, Which; when the blackboard is in position, is"seated on a number of similar suitably spaced" supporting brackets 14 permanently bolted as indicated at 15 to a backing'b'oard 16 which is in turn permanently fastened to the wall. The brackets are horizontally alined and each presents-a bearing 17 to receive the tongue and is. fitted further on the front side with a bearing 1:8, the bean ings .18' being utilized to supp ortlthe lengthwise extendingoperating shaft '19. On:-the1 shaft 1 mount pulleys 20, there being a pulley adjacent each bearing and to the pulleys I secure flexible winding connections 21 such as cords or cables which, after being'passed a few turns around the pulleys, are drawn upwardly behind the blackboard and passed over guiding pulleys 22 permanently secured to the wall, the upper ends being finally fastened to eyes 23 extending from the rear side of the top member 4c of the frame.

. Centrally beneath the blackboard and to the shaft I secure a worm wheel 24: which meshes with a worm 25 mounted on a worm shaft 26, the shaft being carried by a substantially L-shaped hanger 27 permanently secured by bolts 28 to the backing board. The free end of the wormshaft is fitted with a hand wheel 29 supplied with the usual hand grip 30 for convenience in rotating the wheel.

According to the above arrangement it will be obvious that if one turnthe hand wheel in one direction the cables will wind on to the pulleys and consequently pull in the upper end of the blackboard whilevif the hand Wheel be turned in the opposite direction the top end of the blackboard will swing out and in the above actions it will be obvious, owing-to the worm and worm wheel control, that the blackboard will remain set in any position it is left.

Collars 31 and 32 are secured to the shaft 19 adjacent the inner pair of bearings, thus preventing end'play of the shaft.

In order to positively effect the forward swinging of the upperedge of the black board after it has been brought tothe upright position I have provided coil springs 33 fastened in any suitable way such as by staples'34: to the wall and having their free ends extending toward the upper member of the frame so that when the blackboard approaches the upright position the cross member 4 will-strike the springs and compress them; Consequently with the blackboard in the upright position the springs are under compression-and will immediately act to swing the blackboard forwardly the instant the hand wheel is turned in the proper direction to release the cables.

It may be advantageous for one to set the blackboard so that it will always swing out the same distance, this of course depending on the adjustment given, and in order that this can be done I have provided a stop pin 35' which extends forwardly from the hanger 27 in a location. to the side of the worm wheel 24 and have supplied the worm wheel with. a number of spaced adjusting openings 36 which are screw threaded to receive an adjusting pin 37, the openings being positionedrso that in the turning of the Worm Wheel the pin 37 will strike the stationary pin'35; The openings 36 would-be spaced apart fixed predetermined distances, these distances corresponding to stop distances at which it is desired to limit the outward swing of the board.

This arrangement will be better understood by reference to Fig. 2 where it will be seen that the top edge of the blackboard is a certain distance from the wall, say twelve inches, and the adjusting pin 37 is engaged with the stationary pin. No further movement of the worm wheel can occur in the direction indicated by the applied arrow so that with the adjusting pin positioned as shown the upper edge of the board will positively stop swinging outwardly after it has reached a distance of twelve inches away from the vertical or upright position. If the stop pin 37 be unscrewed and placed in another opening the blackboard will stop swinging out in another set position.

By placing one of the holes, so that when the blackboard is in the upright position the pin 37 is engaged with the underside of the pin 35, it will be impossible to turn the hand wheel and accordingly one, such as a child, cannot tamper with the board ifso set.

In adjusting this board one continues tilting the board until the reflected light is thrown below the level of the eyes of the pupils or observers with the resultthat when the adjustment is finally made no glare is apparent and all the material on the -black board is readily visible to all the'observers in the room. r

-- What I claim as my invention is 1. The combination with the wall. of a room, of a blackboard having the lower side thereof pivotally'suspended from the wall, flexible winding connections attached to the upper side of the board and springs interposed between the blackboard and the wall and .engageable with the blackboard and under compression in the vertical position thereof.

2. The combination with the wall of a room, of a blackboard having the lower side thereof pivotally suspended from the wall, a horizontally disposed winding shaft mounted on the wall, hand operated means for rotating the shaft, guide means located on the wall and positioned behind the upper side of the blackboard and flexible connec tions extending from the shaft through the guiding means and attached to theupper side of the blackboard.

3. The combination with the wall of a room,- of a blackboard having the lower side thereof pivotally suspended from the wall, a horizontally disposed winding shaft located below the blackboardand mounted independently thereof, a worm wheel on the shaft, a rotatably mounted worm engaging the worm wheel, a hand wheel for operating the worm, guide pulleys attached to the wall behind the upper side of the blackboard and flexible connections extending from the.

shaft through the guiding means and attached to the upper side of the blackboard;

4C. The combination with the wall of a room, of a plurality of horizontally alined brackets secured to the wall and each providing a bearing in the nature of a cross groove, a blackboard having the lower side thereof fitted with a longitudinally directed downwardly extending tongue pivotally received within the grooves of'the brackets, an operating shaft rotatably' mounted in the brackets, a worm wheel secured tothe shaft, a rotatably mounted worm engaging with the worm wheel, a hand wheel for operating the worm, pulleys secured to the shaft,

guide pulleys located on the wall behind the upper edge of the blackboard and flexible connections attached to the former pulleys and passing around the latter pulleys and having their free ends secured to the upper side of the blackboard.

5. The combination with the wall of a room, of a plurality of horizontally alined brackets secured to the wall and each pro- Gopies ofthis patent may be obtained for viding a bearing in the nature of a cross groove, a blackboard having the lower side thereof fitted with a longitudinally directed downwardly extending tongue pivotally received within the grooves of the brackets, an operating shaft rotatably mounted in the brackets, a worm wheel secured to the shaft,

a rotatably mounted worm engaging with the worm wheel, a hand wheel for operating the worm, pulleys secured to the shaft, guide pulleys located on the wall behind the upper edge of the blackboard, flexible connections attached to the formerpulleys and passing around the latter pulleys and having their V TOM MELLOR.

In the presence of- G. BLAKE, I MAE GILLIEs.

five cents each, by addressing the Commissioner of IPatents,

Washington, D. 0. 

